Rodless cylinder rope tensioning apparatus

Abstract

A rodless cylinder rope tensioning apparatus maintains tension in an endless rope operable for threading a web in a paper-making apparatus and includes at least one rodless cylinder having at least one yoke sheave attached to the internal piston in the rodless cylinder. The rope is initially threaded around an entry guide roller and the yoke sheave and spliced, and then stretched by operation of the rodless cylinder, which selectively causes the piston to relocate the yoke sheave along the length of the rodless cylinder and apply a selected degree of tension to the rope. In a preferred embodiment a pair of entry guide rollers is provided in a frame containing a pair of parallel rodless cylinders, each having a yoke sheave independently movable along the rodless cylinder by operation of the rodless cylinder piston, to effect tensioning of a pair of ropes in the paper-making apparatus. Various air-operated control devices are provided to effect initial threading of the rope on the entry guide roller and yoke sheave, as well as the desired “run”, “paper threading” and safety operations of the rodless cylinder rope tensioning apparatus.

Having described my invention with the particularity set forth above, what is claimed is:  
     
       1. A rodless cylinder rope tensioning apparatus comprising at least one rodless cylinder each comprising a barrel; a piston slidably disposed in said barrel; a distributor valve pneumatically connected to said barrel; a flow valve pneumatically connected to said distributor valve; a first pressure regulator pneumatically connected to said flow valve; a first valve operably connected to said distributor valve and said first pressure regulator for selectively opening said distributor valve and facilitating flow of air from said first pressure regulator through said flow valve and said distributor valve and into said barrel and causing said piston to traverse said barrel in a first direction; a second valve operably connected to said distributor valve and said first pressure regulator for selectively opening said distributor valve and facilitating flow of air from said first pressure regulator, through said flow valve and said distributor valve and into said barrel and causing said piston to traverse said barrel in a second direction; and a yoke sheave connected to said piston for receiving the rope by operation of said first valve and adjusting the tension on the rope responsive to operation of said second valve. 
     
     
       2. The rodless cylinder rope tensioning apparatus of claim  1  wherein said at least one rodless cylinder comprises a pair of rodless cylinders. 
     
     
       3. The rodless cylinder rope tensioning apparatus of claim  1  comprising at least one guide roller provided in substantial alignment with said yoke sheave for receiving the rope and aligning the rope with said yoke sheave. 
     
     
       4. The rodless cylinder rope tensioning apparatus of claim  2  comprising a frame for receiving said rodless cylinders in substantially parallel, spaced-apart relationship with respect to each other. 
     
     
       5. The rodless cylinder rope tensioning apparatus of claim  1  comprising a safety mechanism operably connected to said barrel and said second valve for applying air pressure against movement of said internal piston in said second direction, responsive to operation of said second valve. 
     
     
       6. The rodless cylinder rope tensioning apparatus of claim  1  comprising: 
       (a) at least one guide roller provided in substantial alignment with said yoke sheave for receiving the rope and aligning the rope with said yoke sheave; and  
       (b) a safety mechanism operably connected to said rodless cylinder and said second valve for applying air pressure against movement of said piston in said second direction, responsive to operation of said second valve.  
     
     
       7. The rodless cylinder rope tensioning apparatus of claim  6  wherein said at least one rodless cylinder comprises a pair of rodless cylinders. 
     
     
       8. The rodless cylinder rope tensioning apparatus of claim  7  comprising a frame for receiving said rodless cylinders in substantially parallel, spaced-apart relationship with respect to each other. 
     
     
       9. A rodless cylinder rope tensioning apparatus for tensioning at least one rope in a paper-making machine, said apparatus comprising at least one rodless cylinder each having a barrel including an internal bore, an operating end and a non-operating end; a piston slidably disposed in said internal bore between said operating end and said non-operating end of said barrel; a yoke sheave rotatably carried by said piston, said yoke sheave slidably disposed with said piston; a distributor valve pneumatically connected to said operating end and said non-operating end of said barrel; a flow valve pneumatically connected to said distributor valve; a first pressure regulator pneumatically connected to said flow valve; a first valve pneumatically connected to said distributor valve and said first pressure regulator for selectively opening said distributor valve and facilitating flow of air from said first pressure regulator through said flow valve and said distributor valve and into said non-operating end of said barrel; and a second valve pneumatically connected to said distributor valve and said first pressure regulator for selectively opening said distributor valve and facilitating flow of air from said first pressure regulator, through said flow valve and said distributor valve and into said operating end of said barrel, whereby said piston is caused to selectively traverse said internal bore of said barrel in a first direction for threading the rope on said yoke sheave responsive to operation of said first valve and said piston is caused to selectively traverse said internal bore of said barrel in a second direction for selectively tensioning the rope responsive to operation of said second valve. 
     
     
       10. The rodless cylinder rope tensioning apparatus of claim  9  comprising a third valve operably connected to said bore on said one end of said barrel, for selectively tensioning said yoke sheave in low pressure and high pressure operating modes of said piston in said second direction. 
     
     
       11. The rodless cylinder rope tensioning apparatus of claim  9  comprising a safety mechanism operably connected to said second valve and said internal bore at said other end of said barrel for applying air pressure against movement of said piston in said second direction, responsive to operation of said second valve. 
     
     
       12. The rodless cylinder rope tensioning apparatus of claim  9  comprising: 
       (a) a third valve operably connected to said internal bore on said one end of said barrel, for selectively tensioning said yoke sheave in low pressure and high pressure operating modes on said piston in said second direction; and  
       (b) a safety mechanism operably connected to said second valve and said internal bore at said other end of said barrel for applying air pressure against movement of said piston in said second direction, responsive to operation of said second valve.  
     
     
       13. The rodless cylinder rope tensioning apparatus of claim  9  comprising at least one guide roller provided in substantial alignment with said yoke sheave for receiving the rope and aligning the rope with said yoke sheave. 
     
     
       14. The rodless cylinder rope tensioning apparatus of claim  13  comprising a third valve operably connected to said internal bore on said one end of said barrel, for selectively tensioning said yoke sheave in low pressure and high pressure operating modes on said piston in said second direction. 
     
     
       15. The rodless cylinder rope tensioning apparatus of claim  13  comprising a safety mechanism operably connected to said second valve and said internal bore at said other end of said rodless cylinder for applying air pressure against movement of said piston in said second direction, responsive to operation of said second valve. 
     
     
       16. The rodless cylinder rope tensioning apparatus of claim  13  comprising: 
       (a) a third valve operably connected with said internal bore on said one end of said barrel, for selectively tensioning said yoke sheave in low pressure and high pressure operating modes on said piston in said second direction; and  
       (b) a safety mechanism operably connected to said second valve and said internal bore at said other end of said rodless cylinder for applying air pressure against movement of said piston in said second direction, responsive to operation of said second valve.  
     
     
       17. A rodless cylinder rope tensioning apparatus for tensioning at least one rope in a paper-making machine, said apparatus comprising a pair of rodless cylinders, each of said rodless cylinders having a barrel including an internal bore, an operating end and a non-operating end; a piston slidably disposed in said internal bore between said operating end and said non-operating end of said barrel and a yoke sheave rotatably caried by said piston, said yoke sheave slidably disposed with said piston; a double air piloted distributor valve pneumatically connected to said operating end and said non-operating end of said barrel, a flow valve pneumatically connected to said distributor valve and a pressure regulator pneumatically connected to said flow valve; a first push button valve pneumatically connected to said distributor valve and said pressure regulator for selectively opening said distributor valve and facilitating flow of air from said pressure regulator through said flow valve and said distributor valve and into said non-operating end of said barrel; and a second push button valve pneumatically connected to said distributor valve and said pressure regulator for selectively opening said distributor valve and facilitating flow of air from said pressure regulator, through said flow valve and said distributor valve and into said operating end of said barrel, whereby said piston is caused to selectively traverse said internal bore toward said operating end of said barrel for threading the rope on said yoke sheave, responsive to operation of said first push button valve and said piston is caused to selectively traverse said internal bore toward said non-operating end of said barrel for selectively tensioning the rope in low pressure mode, responsive to operation of said second push button valve. 
     
     
       18. A rodless cylinder rope tensioning apparatus for tensioning at least one rope in a paper-making machine, said apparatus comprising at least one rodless cylinder, each of said at least one rodless cylinder having a barrel including an internal bore, an operating end and a non-operating end; a piston slidably disposed in said internal bore between said operating end and said non-operating end of said barrel and a yoke sheave rotatably carried by said piston, said yoke sheave slidably disposed with said piston; a double air piloted distributor valve pneumatically connected to said operating end and said non-operating end of said barrel; an air piloted flow valve having an air entry port pneumatically connected to said distributor valve and a first pressure regulator pneumatically connected to said air piloted flow valve; a first push button valve pneumatically connected to said distributor valve and said first pressure regulator for selectively opening said distributor valve and facilitating flow of air from said first pressure regulator through said air piloted flow valve and said distributor valve and into said non-operating end of said barrel; a second push button valve pneumatically connected to said distributor valve and said first pressure regulator for selectively open said distributor valve and facilitating flow of air from said first pressure regulator, through said air piloted flow valve and said distributor valve and into said operating end of said barrel, whereby said piston is caused to selectively traverse said internal bore toward said operating end of said barrel for threading the rope on said yoke sheave, responsive to operation of said first push button valve and said piston is caused to selectively traverse said internal bore toward said non-operating end of said barrel for selectively tensioning the rope in low pressure mode, responsive to operation of said second push button valve; a lever valve pneumatically connected to said first pressure regulator and said air piloted flow valve for selectively opening said air entry port in said air piloted flow valve and a second pressure regulator pneumatically connected to said air piloted flow valve at said air entry port, for selectively increasing air pressure flowing in said operating end of said barrel and tensioning said yoke sheave in high pressure mode, responsive to operation of said lever valve during said low pressure mode. 
     
     
       19. A rodless cylinder rope tensioning apparatus for tensioning at least one rope in a paper-making machine, said apparatus comprising at least one rodless cylinder, each of said at least one rodless cylinder having a barrel including an internal bore, an operating end and a non-operating end; a piston slidably disposed in said internal bore between said operating end and said non-operating end of said barrel and a yoke sheave rotatably carried by said piston, said yoke sheave slidably disposed with said piston; a double air piloted distributor valve pneumatically connected to said operating end and said non-operating end of said barrel, a flow valve pneumatically connected to said distributor valve and an adjustable pressure regulator pneumatically connected to said flow valve; a first push button valve pneumatically connected to said distributor valve and said adjustable pressure regulator for selectively opening said distributor valve and facilitating flow of air from said adjustable pressure regulator through said flow valve and said distributor valve and into said non-operating end of said barrel; and a second push button valve pneumatically connected to said distributor valve and said adjustable pressure regulator for selectively opening said distributor valve and facilitating flow of air from said adjustable pressure regulator, through said flow valve and said distributor valve and into said operating end of said barrel, whereby said piston is caused to selectively traverse said internal bore toward said operating end of said barrel for threading the rope on said yoke sheave, responsive to operation of said first push button valve and said piston is caused to selectively traverse said internal bore toward said non-operating end of said barrel for selectively tensioning the rope in low pressure mode, responsive to operation of said second push button valve; an air piloted safety valve pneumatically connected to said non-operating end of said barrel and said distributor valve and an adjustable safety regulator pneumatically connected to said air piloted safety valve for delivering air through said air piloted safety valve to said barrel and applying air pressure against movement of said piston in said low pressure mode, responsive to operation of said second push button valve. 
     
     
       20. A rodless cylinder rope tensioning apparatus for tensioning at least one rope in a paper-making machine, said apparatus comprising at least one rodless cylinder, each of said at least one rodless cylinder having a barrel including an internal bore, an operating end and a non-operating end; a piston slidably disposed in said internal bore between said operating end and said non-operating end of said barrel and a yoke sheave rotatably carried by said piston, said yoke sheave slidably disposed with said piston; a double air piloted distributor valve pneumatically connected to said operating end and said non-operating end of said barrel, a flow valve pneumatically connected to said distributor valve and a first pressure regulator pneumatically connected to said flow valve; a first push button valve pneumatically connected to said distributor valve and said first pressure regulator for selectively opening said distributor valve and facilitating flow of air from said first pressure regulator through said flow valve and said distributor valve and into said non-operating end of said barrel; a second push button valve pneumatically connected to said distributor valve and said first pressure regulator for selectively opening said distributor valve and facilitating flow of air from said first pressure regulator, through said flow valve and said distributor valve and into said operating end of said barrel, whereby said piston is caused to selectively traverse said internal bore toward said operating end of said barrel for threading the rope on said yoke sheave, responsive to operation of said first push button valve and said piston is caused to selectively traverse said internal bore toward said non-operating end of said barrel for selectively tensioning the rope in low pressure mode, responsive to operation of said second push button valve; a lever valve pneumatically connected to said first pressure regulator and said air piloted flow valve for selectively opening said air entry port in said air piloted flow valve and a second pressure regulator pneumatically connected to said air piloted flow valve at said air entry port, for selectively increasing air pressure flowing in said operating end of said barrel and tensioning said yoke sheave in “high pressure” mode, responsive to operation of said lever valve during said “low pressure” mode; and an air piloted safety valve pneumatically connected to said non-operating end of said barrel and said distributor valve and a third pressure regulator pneumatically connected to said air piloted safety valve for delivering air to said barrel and applying air pressure against movement of said piston in said “low pressure” mode, responsive to operation of said second push button valve.